Microorganisms generally live attached to surfaces in many natural, industrial, and medical environments, encapsulated by extracellular substances including biopolymers and macromolecules. The resulting layer of slime encapsulated microorganism is termed a biofilm. Biofilms are the predominant mode of growth of bacteria in the natural environment, and bacteria growing in biofilms exhibit distinct physiological properties. Compared to their planktonically grown counterparts, the bacteria in a biofilm are more resistant to antibiotics, UV irradiation, detergents and the host immune response.
A biofilm may include one or more microorganisms, including gram-positive and gram-negative bacteria, algae, protozoa, and/or yeast or filamentous fungi and viruses and/or bacteriophage. Examples of problematic biofilms are dental plaque, infections on medical implants, but also the initial fouling on ship hulls. Biofilms are attributed to the pathogenesis of many infections in humans and are a significant problem in industry in terms of biofouling of exposed surfaces, where biofilm colonisation can form the base component of a localised ecosystem which can disrupt and interfere with industrial processes and components.
When laundry items like T-shirts or sportswear are used, they are exposed to bacteria from the body of the user and from the rest of the environment in which they are used. Some of these bacteria are capable of adhering to the laundry item and form a biofilm on the item. The presence of bacteria implies that the laundry items become sticky and therefore soil adheres to the sticky areas. This soil has shown difficult to remove by commercially available detergent compositions. Further, when very dirty laundry items are washed together with less dirty laundry items the dirt present in the wash liquor tend to stick to the biofilm. As a result hereof the laundry item is more “soiled” after wash than before wash. Further, these bacteria are a source of bad odor, which develops after use of the laundry item. The bad odor is difficult to remove and may remain even after wash. The reason for this bad odor is adhesion of bacteria to the textile surface. Because of the adhesion to the textile, the bacteria may remain even after wash, and continue to be a source of bad odor.
International patent application WO 2011/098579 concerns bacterial deoxyribonuclease compounds and methods for biofilm disruption and prevention.